The Hudson River is a central feature of New York State’s natural geography. It begins as a little trout stream flowing out of Lake Tear-of-the-Clouds in the Adirondack mountains. It flows and grows southwest and then eastward until, at Hudson Falls, it turns southward for almost 200 miles to meet the Atlantic Ocean at the Verrazano Narrows.

The river runs south between the Catskill mountains to the west and the older Taconic range to the east, through the majestic Hudson Highlands (an extension of the Appalachian range), below which it spreads to its greatest width of over two and a half miles at Haverstraw Bay north of the Tappan Zee. The Hudson runs past the Palisades and into the mouth at New York Bay, 275 nautical miles from its source. Even there it does not stop, for the river's flows have in past centuries carved a 500-mile underwater valley, the Hudson Canyon, with precipices a mile deep in the ocean's floor.